Question

Diprotic acid (H2A), Part II (Homework) Homework. Unanswered For carbonic acid, Kail = 4,5 x 10-7. What is the (HCO3-) in a 0.10 M carbonic acid solution? Respond with the correct number of significant figures in scientific notation (Use E notation and only 1 digit before decimale.g, 2.5E5 for 2.5 x 10" Numeric Answer: Unanswered * Submit

Answer 1

Part ① acid dissociation For carbonic Note: H₂CO3 HCOž +Ht, ka, = 4.54107 Hoy ² cor tht , Ka₂2 4.8x101 In the queustion Kag is not given but you can get this value from any standard reference. As you see that kq, >kaq so we neglect 'the second dissociation.. (In the question Kag is not given so it gives a Hint ! - Second ionization contribution is negligible.) Now, consider first ionization И, co, — Hсо, +н* , initially 0.1om Change ta -x ta A Equilibrium 0.10-4 The equilibrium constant (dissociation Constant Ka= [teCO3] [24t] a x [H₂CO3] 4.5X107 = xin 010-X

we neglect the x in denominaty because ka, is very small volue. ger en x2 2 4.5X10 Xo.10 0.000212 x = 14.5x108 22.128104 m m 2 2.12 x10 m .. ( Hoz 1 = x